[PATCH] [TOPGIT] allow working with annihilated branches

["Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>]

If you decide that you want to drop a patch, you can just merge in its
base with strategy "theirs".  Then you have base=topic and so no .top*
files any more.  This patch fixes tg summary and the helper function
recurse_deps() to handle these annihilated branches as if they don't
exist and don't show up in .topdeps files.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
 tg-summary.sh |   11 ++++++++++-
 tg.sh         |   17 ++++++++++++++++-
 2 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/tg-summary.sh b/tg-summary.sh
index 842d95a..50ee883 100644
--- a/tg-summary.sh
+++ b/tg-summary.sh
@@ -53,13 +53,22 @@ fi
 git for-each-ref refs/top-bases |
 	while read rev type ref; do
 		name="${ref#refs/top-bases/}"
+		if branch_annihilated "$name"; then
+			continue;
+		fi;
+
 		if [ -n "$terse" ]; then
 			echo "$name"
 			continue
 		fi
 		if [ -n "$graphviz" ]; then
 			git cat-file blob "$name:.topdeps" | while read dep; do
-				echo "\"$name\" -> \"$dep\";"
+				dep_is_tgish=true
+				ref_exists "refs/top-bases/$dep"  ||
+					dep_is_tgish=false
+				if ! "$dep_is_tgish" || ! branch_annihilated $dep; then
+					echo "\"$name\" -> \"$dep\";"
+				fi
 			done
 			continue
 		fi
diff --git a/tg.sh b/tg.sh
index ccb40cd..5bb2d0c 100644
--- a/tg.sh
+++ b/tg.sh
@@ -94,6 +94,16 @@ has_remote()
 	[ -n "$base_remote" ] && ref_exists "remotes/$base_remote/$1"
 }
 
+branch_annihilated()
+{
+	_name="$1";
+
+	# use the merge base in case the base is ahead.
+	mb="$(git merge-base "refs/top-bases/$_name" "$_name")";
+
+	test "$(git rev-parse "$mb^{tree}")" = "$(git rev-parse "$_name^{tree}")";
+}
+
 # recurse_deps CMD NAME [BRANCHPATH...]
 # Recursively eval CMD on all dependencies of NAME.
 # CMD can refer to $_name for queried branch name,
@@ -116,7 +126,12 @@ recurse_deps()
 	if has_remote "top-bases/$_name"; then
 		echo "refs/remotes/$base_remote/top-bases/$_name" >>"$_depsfile"
 	fi
-	git cat-file blob "$_name:.topdeps" >>"$_depsfile"
+
+	# if the branch was annihilated, there exists no .topdeps file
+	if ! branch_annihilated "$_name"; then
+		#TODO: handle nonexisting .topdeps?
+		git cat-file blob "$_name:.topdeps" >>"$_depsfile";
+	fi;
 
 	_ret=0
 	while read _dep; do
-- 
1.5.6.5